Method for transferring and placing beads for tyres, device for carrying out such a method and spacer to be used in such a method and/or device

ABSTRACT

Method for transferring and placing beads for tyres, providing:
         a bead storage unit in which a number of beads are vertically stacked placing spacers in between them, a collection unit for empty spacers, placed in the vicinity of the bead storage unit,   a tyre building machine for receiving the beads thereon,   a bead retaining means for picking up and retaining a bead, wherein the bead retaining means is provided with engagement jaws that are arranged at equal angular distance in a circumferential direction on the bead retaining means, wherein the engagement jaws are driven or withdrawn in radial direction,   a spacer retaining means for picking up and retaining a spacer, and   arranging the bead retaining means and the spacer retaining means on a common transfer means. The spacer retaining means is provided with at least two spacer engagement jaws that are arranged at equal angular distance in a circumferential direction on the spacer retaining means, wherein the spacer engagement jaws are driven or withdrawn in radial direction.

BACKGROUND OF THE INVENTION

The present invention relates to a method for transferring and placingbeads for tyres, comprising the steps of:

providing a bead storage unit in which a number of beads are verticallystacked placing spacers in between them,

providing a collection unit for empty spacers, which collection unit isplaced in the vicinity of the bead storage unit,

providing a tyre building machine for receiving the beads thereon,

providing a bead retaining means for picking up and retaining a bead,wherein the bead retaining means is provided with engagement jaws thatare arranged at equal angular distance in a circumferential direction onthe bead retaining means, wherein the engagement jaws are driven orwithdrawn in radial direction,

providing a spacer retaining means for picking up and retaining aspacer, and

arranging the bead retaining means and the spacer retaining means on acommon transfer means.

Such a method is known from EP-B1-0567652. In that method the spacerretaining means is formed by drawing means placed radially outside ofthe bead engagement jaws, which drawing means are able to pick up andretain the spacers by vacuum or magnetic force. For that purpose thedrawing means are designed so as to be upwardly and downwardly movable.

SUMMARY OF THE INVENTION

It is among others an object of the present invention to provide analternative method for transferring and placing beads for tyres.

For that purpose according to the invention a method of the typementioned in the preamble is characterised in that the method comprisesthe steps of:

providing the spacer retaining means with at least two spacer engagementjaws that are arranged at equal angular distance in a circumferentialdirection on the spacer retaining means, wherein the spacer engagementjaws are driven or withdrawn in radial direction. By instead of theknown drawing means that can move upwards and downwards by means ofvacuum or magnetic force, using spacer engagement jaws according to theinvention that can be radially driven or withdrawn, an alternativemethod is provided that can be carried out relatively easily andaccurately.

In one embodiment of a method according to the invention the methodcomprises the steps of:

providing the spacer retaining means with two spacer engagement jawsplaced opposite each other, wherein the engagement jaws are driven orwithdrawn in radial direction, and

providing the spacer retaining means with two balancing pins placedopposite each other and at equal angular distance between the spacerengagement jaws. In that way the spacer retaining means is made with arelatively low number of movable parts, as a result of which the methodcan be carried out relatively easily.

In a further embodiment of a method according to the invention, themethod comprises the steps of:

providing the spacer with a central aperture, wherein the spacer isprovided with an inner ring defining the central aperture,

placing the spacer engagement jaws radially in the central aperture,

driving the spacer engagement jaws in radial direction until they willengage the inner ring. In that way the spacer retaining means isdesigned compact and picking up the spacers only requires a slightmovement of the spacer engagement jaws, as a result of which the methodcan be carried out relatively fast.

In one further embodiment of a method according to the invention themethod comprises the steps of:

providing the spacer with a conical surface, which conical surfaceencloses a spacer angle having a value in a range of approximately 8° toapproximately 20°,

at said spacer angle in radial direction driving or withdrawing thespacer engagement jaws and the bead engagement jaws. In particular saidmethod comprises the steps of:

providing the bead with a bead apex that is at a bead apex angle, and

choosing a spacer angle that is approximately 1° to approximately 3°smaller than the bead apex angle. As the bead is usually placed on thespacer when still in a hot condition, said choice of the spacer angleensures that the bead and particularly the bead apex is supported withas little deformation of the bead apex as possible. In that way themethod is able to ensure a highly accurately manufacturing of tyres.

In an advantageous embodiment of a method according to the invention themethod comprises the steps of:

picking up and retaining a bead with related spacer from a stack ofbeads including spacers from the bead storage unit,

moving the picked up and retained bead including related spacer to thecollection unit for empty spacers, wherein during the movement the beadretaining means picks up the bead from the spacer and retains it. As thebead is picked up from the spacer during the movement of the bead andthe related spacer to the collection unit for empty spacers, it isensured that the method can be carried out relatively fast. After thespacer has been placed on the collection unit, the bead can immediatelybe conveyed further to the tyre building machine, without an additionalaction being needed.

The invention furthermore relates to a device for carrying out themethod according to the invention, which device is provided with

a bead storage unit for vertically stacking a number of beads in therewhile placing spacers in between them,

a collection unit for empty spacers, which collection unit can be placedin the vicinity of the bead storage unit,

a tyre building machine adapted for receiving beads thereon,

a bead retaining means for picking up and retaining a bead, wherein thebead retaining means is provided with engagement jaws that are arrangedat equal angular distance in a circumferential direction on the beadretaining means, wherein the engagement jaws can be driven or withdrawnin radial direction,

a spacer retaining means for picking up and retaining a spacer,

wherein the bead retaining means and the spacer retaining means arearranged on a common transfer means,

wherein the spacer retaining means is provided with at least two spacerengagement jaws that are arranged at equal angular distance in acircumferential direction on the spacer retaining means, wherein thespacer engagement jaws can be driven or withdrawn in radial direction.

In one embodiment of a device according to the invention the spacerretaining means is provided with two spacer engagement jaws placedopposite each other, wherein the engagement jaws can be driven orwithdrawn in radial direction, and the spacer retaining means is furtherprovided with two balancing pins placed opposite each other and at equalangular distance between the spacer engagement jaws.

In one further embodiment of a device according to the invention, thedevice contains spacers, wherein each spacer is provided with a centralaperture, wherein the spacer is provided with an inner ring defining thecentral aperture, and that the spacer engagement jaws in a firstposition can be placed radially in the central aperture, and can beplaced in a second position in which the spacer engagement jaws are inengagement with the inner ring.

In a further embodiment of said device the spacer is provided with aconical surface, which conical surface encloses a spacer angle having avalue in a range of approximately 8° to approximately 20°, and thespacer engagement jaws and the bead engagement jaws can be driven orwithdrawn in radial direction at said spacer angle. In particular saiddevice comprises a bead having a bead apex that is at a bead apex angle,wherein the spacer angle is approximately 1° to approximately 3° smallerthan the bead apex angle.

In a further embodiment of a device according to the invention thedevice is provided with a servomotor and a cardan joint for the beadengagement jaws.

In yet a further embodiment of a device according to the invention thedevice is provided with a pneumatic drive for the spacer engagementjaws.

In an advantageous embodiment of a device according to the invention thetransfer means is further provided with tyre engagement jaws forengaging a green tyre and for removing the green tyre from the tyrebuilding machine.

In a further embodiment of a device according to the invention thetransfer means is further provided with tyre engagement jaws forengaging a green tyre and for removing a green tyre from the tyrebuilding machine. In this way a separate unit for removing the greentyre will not be required.

The invention further relates to a spacer to be used in the methodaccording to the invention and/or to be used in a device according tothe invention, wherein the spacer is provided with a conical surface,which conical surface encloses a spacer angle having a value in a rangeof approximately 8° to approximately 20°.

In one embodiment of a spacer according to the invention the spacer isprovided with an inner ring defining a central aperture, wherein theinner ring is provided with an upright edge.

In a further embodiment of a spacer according to the invention thespacer is provided with four slots arranged in a cross-shape. Said slotsamong others have a cooling purpose by allowing air circulation, andfacilitate the removal of spacers from one another.

The aspects and measures described in this description and the claims ofthe application and/or shown in the drawings of this application maywhere possible also be used individually. Said individual aspects, suchas particularly applying to the measures and aspects described per se inthe sub claims, may be the subject of divisional patent applicationsrelating thereto.

SHORT DESCRIPTION OF THE DRAWINGS

The invention will be elucidated on the basis of a number of exemplaryembodiments shown in the attached drawings, in which:

FIG. 1 shows a schematic top view of a device for carrying out a methodfor transferring and placing beads for tyres,

FIG. 2 shows a schematic top view of a unit for manufacturing beads andfor placing such beads on a mobile part of a bead storage unit,

FIG. 3 shows a schematic side view of a mobile part as shown in FIG. 2,

FIGS. 4A-4C show schematically and in perspective a common transfermeans part of the device as shown in FIG. 1, wherein a bead retainingmeans and a spacer retaining means have been arranged on the transfermeans,

FIGS. 5A-5E schematically show in cross-section some steps of picking upand retaining a spacer including bead by the bead retaining means andthe spacer retaining means,

FIGS. 6A and 6B show schematically and in perspective a spacer to beused in a device according to FIG. 1, and

FIG. 6C shows a schematic view in cross-section of a stack of beadswhile placing spacers in between them.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 schematically shows a top view of a device for carrying out amethod for transferring and placing beads for tyres. The device isprovided with a bead storage unit for vertically stacking a number ofbeads 12 in there while placing spacers 13 in between them. In theembodiment shown the bead storage unit comprises a first conveyor belt9, on which (in the embodiment shown) three stacks of beads have beenarranged. The beads placed on said conveyor belt have the same diameter.Furthermore a second conveyor belt 10 is provided with (in theembodiment shown) two stacks 4, 5 of beads having the same diameter thatdiffers from the diameter of the beads placed on the first conveyor belt9. A third conveyor belt 11 is furthermore provided on which (in theembodiment shown) three stacks 6, 7, 8 of beads have been placed thathave the same diameter, which diameter differs from the diameter of thebeads placed on the first conveyor belt 9 and which differs from thediameter of the beads placed on the second conveyor belt 10.

In FIG. 1 it is also indicated that a mobile unit 14 on which a stack ofbeads intended for the second conveyor belt is arranged, is placed atthe feed end of the second conveyor belt 10. Said stack of beads (withspacers placed in between them), as indicated by the arrow, can betransferred onto the second conveyor belt.

The device further comprises a collection unit for empty spacers 13.Said collection unit is placed in the vicinity of the bead storage unit,as shown in FIG. 1. In the embodiment as shown in FIG. 1 the collectionunit for empty spacers contains a conveyor belt 15 on which (in theembodiment shown) two vertical stacks of empty spacers (that meansspacers without beads) have been placed. In FIG. 1 a mobile unit 16 isfurthermore shown on which a vertical stack of empty spacers has justbeen placed. For that purpose the conveyor belt 15 can be driven asindicated by the arrow.

The device further comprises a tyre building machine 17 adapted forreceiving beads thereon. In the embodiment shown in FIG. 1 the tyrebuilding machine 17 comprises among others a rotatable building drum 18,a unit 19 for placing beads (also called “bead setter”), a loadingdevice 20 (also called “bead loader”) for loading beads thereon, and aunit 21 for removing a ready green tyre 22 from the building drum 18,which unit 21 can be moved with respect to the building drum 18 (or viceversa). Such a tyre building machine is known per se and therefore willnot be discussed here in further detail.

As shown in FIG. 1 the device further comprises a common transfer means23 for transferring beads to the bead loader 20. The common transfermeans 23 for that purpose carries a bead retaining means to be furtherclarified below as well as a spacer retaining means. The common transfermeans 23 in the embodiment shown in FIG. 1 is carried by a movable robotarm 24, that is movable such that the beads can be transferred to thebead loader 20 and empty spacers can be transferred to the conveyor belt15. It is possible here to first remove a spacer including bead from astack, for instance stack 1, and place it on the conveyor belt 15 (orplace it on an empty spacer positioned thereon), and after that removingthe bead from the spacer and transferring the bead to the bead loader.Alternatively the bead can also be removed from the spacer on the stack1 and be transferred to the bead loader, after which the transfer means23 returns to the stack 1 for picking up the empty spacer and place iton the conveyor belt 15 (or on an empty spacer positioned thereon). Theinvention, however, provides a further alternative, namely one in whichthe bead retaining means already picks up the bead from the spacer andretains it during the movement of a bead with related spacer that ispicked up from a vertical stack of beads with spacers and retained, tothe collection unit for empty spacers. Because during the movement ofthe bead and the related spacer to the collection unit for empty spacersthe bead is picked up from said spacer, it is ensured that the methodcan be carried out relatively fast. After the spacer is placed on thecollection unit, the bead can be immediately conveyed further to thetyre building machine, without an additional action being necessary. Itwill be clear that instead of by a robot arm the common transfer meanscan also be moved by means of a rail system or another alternativemeans.

FIG. 2 schematically shows a top view of a unit for manufacturing beadsand for placing such beads on a mobile part of a bead storage unit. Inthis unit (known per se) a bead core 25 and a bead apex 26 are assembledinto a bead 12 in a manner known per se, and therefore not furtherdescribed herein. The manufactured (still warm) bead 12 is directlyautomatically placed on an empty spacer 13 (as indicated by the arrow),and subsequently the spacer 13 including bead 12 is stacked onto avertical stack 27. Said vertical stack 27 is placed on a conveyor belt28 which conveys stacks of the desired height to the mobile unit 14.Said mobile unit 14 can subsequently be moved by an operator orautomatically to the conveyor belt 10 of FIG. 1.

For the sake of the stacking accuracy of the vertical stack of spacerson the mobile unit, on the one hand spacers are provided with squarerecesses 29 that are formed for accommodating a guide 30 withprotrusions 31 that are arranged on the mobile unit 14. In that wayrotation of the vertical stack of spacers is counteracted as much aspossible. It will be clear that the recesses shown in FIG. 2 and theshape of the protrusions of the guide can be designed differently. FIG.3 schematically shows a side view of the mobile unit 14 with a stack 27′of spacers placed thereon. It can clearly be seen here that the guide 30inclines slightly backwards, and a bearing area 32 of the stack isplaced inclined, so that the stack during conveyance remains in aproperly defined position. Optionally the bearing area can be moved asregards height. It will be clear that the invention is not limited tothe shown embodiment of a mobile unit but that many alternatives formoving a vertical stack of spacers with beads can be used. However, theembodiment shown as regards efficiency and simplicity is preferred. Itwill furthermore be clear that a mobile unit 16 comparable to the mobileunit 14 can be used for conveying vertical stacks of empty spacers fromthe device as shown in FIG. 1 to the unit as shown in FIG. 2.

FIGS. 4A-4C schematically and in perspective show a common transfermeans 23 that is part of the device as shown in FIG. 1, wherein a beadretaining means 33 and spacer retaining means 34 are arranged on thetransfer means 23. In this case the depiction of FIG. 4B is rotated 90°with respect to the depiction in FIG. 4A, and in FIGS. 4A and 4B a topview and in FIG. 4C a bottom view is shown.

The bead retaining means for picking up and retaining a bead is providedwith (in the embodiment shown four) engagement jaws 33 that are arrangedat equal angular distance in a circumferential direction on the beadretaining means 23 on radially extending arms 42, 43, 44, 45, whereinthe engagement jaws 33 can be driven or withdrawn in radial direction.For that purpose a servomotor 35 is provided which by means of amultiple cardan joint 36 drives the bead engagement jaws 33. As a resultan accurate and simultaneous drive of the engagement jaws 33 will becomepossible in a simple manner.

The common transfer means 23 further carries a spacer retaining means 34for picking up and retaining a spacer. The spacer retaining means 34 isprovided with two spacer engagement jaws 37, 38 which are arranged atequal angular distance in a circumferential direction on the spacerretaining means 34, wherein the spacer engagement jaws 37, 38 can bedriven or withdrawn in radial direction, in the embodiment shown by apneumatic drive 39. The spacer retaining means 34 is furthermoreprovided with two balancing pins 40, 41 placed opposite each other andat equal angular distance between the spacer engagement jaws 37, 38. Thespacer engagement jaws 37, 38 engage onto corresponding recesses thatare arranged in the spacer.

In an advantageous embodiment the transfer means 23 is furthermoreprovided with tyre engagement jaws 46, 47, 48, 49 for engaging a greentyre and for removing the green tyre from the tyre building machine,particularly its unit 21 (see FIG. 1). In this way a separate unit forremoving the green tyre will not be necessary. In the embodiment shownin FIG. 4 the tyre engagement jaws 46, 47, 48, 49 are placed at the endsof the arms 42, 43, 44, 45, and the engagement jaws 33 are arranged atthe tyre engagement jaws. Please note that the tyre engagement jaws,just like the bead engagement jaws, can be driven and withdrawn inradial direction, so drivable and withdrawable in radial direction. Withthese tyre engagement jaws a pin can be arranged, which prevents thatthe green tyre sticks to the engagement jaws.

FIGS. 5A-5C schematically show in cross-section some steps of picking upand retaining a spacer 13 including bead 12 by the bead retaining meansand the spacer retaining means. The spacer 13 contains a centralaperture 50, wherein the spacer 13 is provided with an inner ring 51defining the central aperture 50 (see FIGS. 5C and 6A). The spacerengagement jaws 37, 38 in a first position can be placed radially in thecentral aperture 50, after which the pneumatic drive places them in asecond position (see FIG. 5A) in which the spacer engagement jaws are inengagement with the inner ring 51, particularly a recess 52 (FIG. 6C)therein.

In the embodiment shown in the figures the spacer 13 is provided with aconical surface 53, which conical surface 53 encloses a spacer angle α(FIG. 6C), wherein α has a value in a range of approximately 8° toapproximately 20°. The spacer engagement jaws 37, 38 and the beadengagement jaws 33 can be driven or withdrawn in radial direction atsaid spacer angle. As regards construction this can be realisedrelatively easily by mounting the arms 42, 43, 44, 45 at said spacerangle α (see FIG. 5A).

Although the surface of the spacers can be flat, due to preserving theshape of the bead it is preferred that the surface is conical having aspacer angle α that is approximately 1° to approximately 3° smaller thana bead apex angle α′ enclosing the bead apex 26 with the horizontal(when placed on a horizontal surface) (FIG. 6C). Preferably said angleis chosen such that the inner edge circumference 54 of the bead core 25as well as the outer circumference 55 of the bead apex 26 after placingthe bead on the spacer are supported on the conical surface, without theoriginal shape (which is the shape immediately after manufacturing) ofthe bead changing.

As shown in FIG. 5A the spacer engagement jaws 37, 38 engage into therelated recesses 52 in the spacer. It may happen that the spacer 13tilts slightly, because only two spacer engagement jaws are being used.The two pins 40, 41 have indeed been arranged to ensure that saidtilting does not become too great, and therefore ensure balance. In FIG.5B (rotated 90° with respect to FIG. 5A) it can be seen that one of thepins, pin 41, ensures a balance supporting point.

Subsequently the spacer 13 with the bead 12 positioned thereon is liftedfrom the stack (FIG. 5C), and the spacer 13 and the bead 12 are placedon top of a stack of empty spacers, and the spacer engagement jaws arewithdrawn so that the spacer is released (FIG. 5D).

After that or simultaneously therewith the bead engagement jaws 33 aredriven radially to the outside (by driving the servomotor and themultiple cardan joint), until the engagement jaws 33 engage the bead 12,after which the bead is lifted from the spacer stack (FIG. 5E). It willbe clear that all this can be controlled such that first the bead willbe removed from the spacer, so that the bead can be transferred to thebead loader, after which the empty spacer can be removed from the stack.

FIGS. 6A and 6B schematically show in perspective a spacer to be used ina device according to FIG. 1 and FIG. 6C shows a schematic view incross-section of a stack of beads with spacers placed in between them.The spacer has been described in some detail above. In FIGS. 6A and 6Bis can furthermore be seen that the spacer 13 is provided with fourslots 56, 57, 58, 59 arranged in a cross-shape, which ensure a coolingfunction during intermediate storage (transportation via the mobileunit). A second function of said slots is to facilitate the removal ofthe spacer from a spacer situated below it. Without such slots whenremoving a spacer a vacuum could be created so that the spacer below itmight remain stuck to the spacer on top of it.

The spacer 13 further has an upright inner edge 60, which is slightlysmaller than the smallest inner diameter of the bead, and an uprightouter edge 61, which is slightly larger than the largest outer diameterof a bead. In this way it is prevented that the bead may get beyond thecircumferential edges of the spacer.

The spacers 13 are designed such (FIG. 6C) that for maintaining a properstacking accuracy they support on each other at both the inner ring 51and on the outer edge 61 (provided with a supporting edge 62) foroptimal stability of the stack. Here a slit 64 (FIG. 6C) is formedbetween the outer edge 61 of the spacer lying underneath and a spacerlying on top, which allows sufficient air circulation for cooling.

For improving the stacking accuracy the spacer is designed substantiallysquare, having the recesses 29 at one side, and bevellings 63 at theother side. The spacer has edges along the slots 56, 57, 58, 59 andpreferably a waver pattern of edges (not shown), to reduce the abutmentsurface of the bead on the spacer, so that the bead “sticking” to thespacer is reduced.

The spacer shown in FIG. 6 is able to carry beads having dimensions in arange of approximately 13 inches to approximately 24 inches, whereinboth the smallest size and the largest size are bounded by the inneredge 60 and the outer edge 61.

Below a short description follows of the method for transferring a beadwherein reference is made to FIG. 1.

Full stacks of spacers (that means including beads) are and will beplaced by the mobile unit 14 on the conveyor path (in the directionindicated by arrow A for the stack related to the conveyor belt 10).

The spacer retaining means takes the spacer with the bead from thestack, because the two spacer engagement jaws arranged at equal angulardistance in a circumferential direction on the spacer retaining meansare driven in radial direction, arrow B in FIG. 1.

Subsequently the spacer with bead assembly is placed on an empty stack13 on the conveyor belt 15, arrow C, and the spacer is released becausethe two spacer engagement jaws arranged at equal angular distance in acircumferential direction on the spacer retaining means, are withdrawnin radial direction.

The bead is removed from the spacer because the bead engagement jaws aredriven in radial direction and loaded in the bead loader 20 (arrow D).Please note that this has to be done twice per green tyre.

After the green tyre 22 is finished it is removed from the unit 21 byradially moving the tyre engagement jaws.

The empty stack of spacers on the conveyor belt 15 is removed from theconveyor belt 15 by a mobile unit 16, and conveyed to a unit formanufacturing new beads (FIG. 2).

The above description is included to illustrate the operation ofpreferred embodiments of the invention and not to limit the scope of theinvention. Starting from the above explanation many variations that fallwithin the spirit and scope of the present invention, particularly asdefined in the attached claims, will be evident to an expert.

1. Method for transferring and placing beads for tyres, comprising thesteps of: providing a bead storage unit in which a number of beads arevertically stacked placing spacers in between them, providing acollection unit for empty spacers, which collection unit is placed inthe vicinity of the bead storage unit, providing a tyre building machinefor receiving the beads thereon, providing a bead retaining means forpicking up and retaining a bead, wherein the bead retaining means isprovided with engagement jaws that are arranged at equal angulardistance in a circumferential direction on the bead retaining means,wherein the engagement jaws are driven or withdrawn in radial direction,providing a spacer retaining means for picking up and retaining aspacer, and arranging the bead retaining means and the spacer retainingmeans on a common transfer means, characterised in that the methodcomprises the steps of: providing the spacer retaining means with atleast two spacer engagement jaws that are arranged at equal angulardistance in a circumferential direction on the spacer retaining means,wherein the spacer engagement jaws are driven or withdrawn in radialdirection.
 2. Method according to claim 1, characterised in that themethod comprises the steps of: providing the spacer retaining means withtwo spacer engagement jaws placed opposite each other, wherein theengagement jaws are driven or withdrawn in radial direction, andproviding the spacer retaining means with two balancing pins placedopposite each other and at equal angular distance between the spacerengagement jaws.
 3. Method according to claim 1, characterised in thatthe method comprises the steps of: providing the spacer with a centralaperture, wherein the spacer is provided with an inner ring defining thecentral aperture, placing the spacer engagement jaws radially in thecentral aperture, driving the spacer engagement jaws in radial directionuntil they will engage the inner ring.
 4. Method according to claim 1,characterised in that the method comprises the steps of: providing thespacer with a conical surface, which conical surface encloses a spacerangle having a value in a range of approximately 8° to approximately20°, at said spacer angle in radial direction driving or withdrawing thespacer engagement jaws and the bead engagement jaws.
 5. Method accordingto claim 4, characterised in that the method comprises the steps of:providing the bead with a bead apex that is at a bead apex angle, andchoosing a spacer angle that is approximately 1° to approximately 3°smaller than the bead apex angle.
 6. Method according to claim 1,characterised in that the method comprises the steps of: picking up andretaining a bead with related spacer from a stack of beads includingspacers from the bead storage unit, moving the picked up and retainedbead including related spacer to the collection unit for empty spacers,wherein during the movement the bead retaining means picks up the beadfrom the spacer and retains it.
 7. Device for carrying out the methodaccording to claim 1, which device is provided with a bead storage unitfor vertically stacking a number of beads in there while placing spacersin between them, a collection unit for empty spacers, which collectionunit can be placed in the vicinity of the bead storage unit, a tyrebuilding machine adapted for receiving beads thereon, a bead retainingmeans for picking up and retaining a bead, wherein the bead retainingmeans is provided with engagement jaws that are arranged at equalangular distance in a circumferential direction on the bead retainingmeans, wherein the engagement jaws can be driven or withdrawn in radialdirection, a spacer retaining means for picking up and retaining aspacer, wherein the bead retaining means and the spacer retaining meansare arranged on a common transfer means, wherein the spacer retainingmeans is provided with at least two spacer engagement jaws that arearranged at equal angular distance in a circumferential direction on thespacer retaining means, wherein the spacer engagement jaws can be drivenor withdrawn in radial direction.
 8. Device according to claim 7,characterised in that the spacer retaining means is provided with twospacer engagement jaws placed opposite each other, wherein theengagement jaws can be driven or withdrawn in radial direction, and thespacer retaining means is further provided with two balancing pinsplaced opposite each other and at equal angular distance between thespacer engagement jaws.
 9. Device according to claim 7, characterised inthat the device contains spacers, wherein each spacer is provided with acentral aperture, wherein the spacer is provided with an inner ringdefining the central aperture, and in that the spacer engagement jaws ina first position can be placed radially in the central aperture, and canbe placed in a second position in which the spacer engagement jaws arein engagement with the inner ring.
 10. Device according to claim 9,characterised in that the spacer is provided with a conical surface,which conical surface encloses a spacer angle having a value in a rangeof approximately 8° to approximately 20°, and in that the spacerengagement jaws and the bead engagement jaws can be driven or withdrawnin radial direction at said bead angle.
 11. Device according to claim10, characterised in that the device comprises a bead having a bead apexthat is at a bead apex angle, wherein the spacer angle is approximately1° to approximately 3° smaller than the bead apex angle.
 12. Deviceaccording to claim 7, characterised in that the device is provided witha servomotor and a cardan joint for the bead engagement jaws.
 13. Deviceaccording to claim 7, characterised in that the device is provided witha pneumatic drive for the spacer engagement jaws.
 14. Device accordingto claim 7, characterised in that the transfer means is further providedwith tyre engagement jaws for engaging a green tyre and for removing thegreen tyre from the tyre building machine. In this way a separate unitfor removing the green tyre will not be required.
 15. Spacer to be usedin the method according to claim 1, characterised in that the spacer isprovided with a conical surface, which conical surface encloses a spacerangle having a value in a range of approximately 8° to approximately20°.
 16. Spacer according to claim 15, characterised in that the spaceris provided with an inner ring defining a central aperture, wherein theinner ring is provided with an upright edge.
 17. Spacer according toclaim 15, characterised in that the spacer is provided with four slotsarranged in a cross-shape.